Bragg Spectroscopy of ultracold Fermi gas paper published in PRL

Researchers at Swinburne's Centre for Atom Optics and Ultrafast Spectroscopy (CAOUS) have recently succeeded in performing the first study of pairing in ultra cold Fermi gases using Bragg spectroscopy. This work may help us identify the role pairing plays in creating fermionic superfluids. Such superfluids display remarkable properties such as flow without resistance, or in the case of superconductors, the flow of current without any loss of power.

Ultracold Fermi gases offer a pristine and highly controllable resource to probe the fundamental behaviour of these quantum systems. This research utilised a gas of fermionic ⁶Li atoms cooled to below one millionth of a degree above absolute zero, some of the coldest known temperatures in the universe. The Cold Molecules lab at Swinburne, founded as part of the ARC Centre of Excellence for Quantum Atom Optics, is the only lab in the southern hemisphere capable of producing such ultracold fermionic systems.

The Swinburne team, lead by Dr Chris Vale, have shown how the technique of Bragg spectroscopy can be used as a new probe of the pair correlations in these strongly interacting quantum systems, which are responsible for superfluidity. The team are now investigating the temperature dependence of pairing to try to understand how these pair correlations build up as the atoms are cooled to lower and lower temperatures.

The work has been published in Physical Review Letters.

Link to paper: G. Veeravalli et al., Phys. Rev. Lett. 101, 250403 (2008) arXiv:0809.2145